From the state of the art seat belts are known, wherein a restraining element, a so-called a strap button, is provided in order to hold a seat belt tongue in a predefined position in a parking position of a belt system (while the belt is not fastened). This strap button is made of two or more parts which are pierced or pushed on both sides through the belt webbing of the seat belt and are held together by means of a clip or pin connection. The strap button prevents the seat belt tongue from resting on the seat cushion in the inoperative position and allows the seat belt tongue to be positioned in the desired position to be conveniently accessed by a user. A strap button of this type is known from US 2004/0250387 A1.
The strap button protruding from the seat belt on both side surfaces of belt webbing in accordance with the prior art creates an aesthetic impairment and makes it necessary to configure the seat belt tongue on the side facing away from the seat cushion such that the seat belt tongue can be suspended in a flat manner in the inoperative position and rest against the seat belt.
Penetration of the seat belt webbing entirely through its thickness when the strap button elements are joined results in weakening of the webbing material. In addition, if inflatable seat belts are used, it is difficult to guarantee sufficient gas flow in the region of the strap button since the prior art connection approach prevents the webbing from being easily inflated and provides clearance for the flow of gas through its interior.
DE 103 27 753 A1 describes a sensor arrangement to be attached to a belt, particularly to a seat belt of a motor vehicle, wherein a sensor is attached to the belt on the upper side of the belt facing away from the passenger. The sensors determine the heart rate, for example, or the body temperature, or they can be configured as microphones.
It is the object of the present invention to provide a seat belt which is comfortable to use, provides occupant safety, and is visually appealing.
This object of the invention is achieved according to the invention by a seat belt having the characteristics described herein. Advantageous embodiments and further developments of invention are also disclosed.
The seat belt for motor vehicles according to the invention, includes a restraining element for a seat belt tongue, the element protruding from the seat belt, provides for a one-sided arrangement of the restraining element on the seat belt such that one side of the seat belt, preferably the side facing the user of the belt, has no projecting or protruding restraining element or a belt buckle latch stopper. In the parking position, the buckle latch rests flat against the seat belt since the restraining element visibly and effectively projects only on the seat belt back surface. In this way, in the parking position, protrusion of the belt front surface in the direction of the vehicle interior is eliminated. The invention further provides that the seat belt may be configured as a multi-layer seat belt comprising a hollow space, wherein the belt can be filled with an appropriate gas via a gas generator. This hollow space is formed by a plurality of seat belt layers and is used for inflatable seat belt systems.
In order to be able to also use seat belt tongues that have a wider belt slot, it is provided that the restraining element of this invention is at least 4 mm thick in order to be able to guarantee secure fastening of the seat belt tongue in the desired position.
Likewise, it is possible that the restraining element extends at least across half the width of the seat belt, preferably across nearly the entire width of the belt webbing, in order to cover corresponding slot cross-sections and thus guarantee secure association of the seat belt tongue with the seat belt. On the correspondingly large restraining elements, a label with informational content may be applied, which provides information, for example, about the design features or the properties of the seat belt, or warnings required by regulations. In this case, the restraining element is preferably disposed on the visible side surface of the belt webbing such that the informational content of the label can be identified by the belt user. Furthermore, arranging the restraining element on the visible side surface has the advantage that, particularly in the case of belt systems integrated in the seat, the restraining element does not negatively influence the storage position, thus producing an orderly appearance overall.
It is provided that the restraining element is fastened in the conventional manner to the seat belt layer, which is to say it is positively fastened by a mechanical fastener to the inside of the seat belt to a layer of the seat belt in order to fix the seat belt tongue in place. A basic alternative to the positive mechanical attachment is to glue or weld it on as a non-positive or bonded connection of the restraining element to one side of the seat belt or one side surface of a seat belt layer.
In all cases this ensures that the inflation behavior of an inflatable seat belt is not changed and that using comfort is not impaired by the fact that part of the restraining element is disposed on the side surface facing the belt user in the operating or usage position. To this end, the restraining element is preferably disposed on the side surface of the seat belt fading the backrest cushion.